Probes are often used for measuring acidity level (pH), temperature, and antigens of substances and test samples. Conventional probes typically are too large to make localized measurements, thus making pH, temperature, and antigen measurements in micro scale such as in a single cell, in a specific local spot, and micro-scale gradient change difficult. This particularly prevents intracellular measurements from being taken. Some conventional probes can make intracellular measurements but not without destroying the cell being probed.